Rick Deckard is a "Blade Runner", a special agent in the Los Angeles police department employed to hunt down and "retire" replicants. His ID number is B-263-54, which is stated twice in both the 1992 Director's Cut and the 25th-anniversary Final Cut of the film.

Roy Batty is the leader of the renegade Nexus-6 replicants and the main antagonist of the film. He was activated on January 8, 2016, which makes him 3 years and 10 months old by the time of the events of the film. He is highly intelligent, fast, and skilled at combat, and yet still learning how to deal with developing emotions. With an A Physical Level (superhuman strength & endurance) and an A Mental Level (genius-level intellect), he is probably the most dangerous of all the fugitive replicants. He is a combat model, used off-world for military service. He and three other replicants come to Earth hoping to find a way to lengthen their lifespan. He is able to use J. F. Sebastian to get a meeting with Tyrell, the head founder of the company and his creator. Tyrell refers to him as his "prodigal son", and tells him his life cannot be extended, but that he should revel in the life that he has, as he has done and seen things others could only dream of. Following this, Batty kills Tyrell and likely is the killer of Sebastian.

Deckard retires the remaining replicants and is hunted by a dying Roy. Trying to escape, Deckard ends up dangling from a building and is saved from the fall by Roy. As he dies, Roy tells Deckard about the things he saw in his life and how all those memories would be gone forever. He then smiles, saying, "Time… to die", and passes away.

In the original novel, Do Androids Dream of Electric Sheep?, his name was spelled "Roy Baty", and was the leader of the eight androids who killed their human owners so that they could escape their life of slavery on Mars. Roy was married to Irmgard Baty, another android. In the novel, Roy's relationship with Pris (who was his lover in the film) is only one of friendship.

In the novel Blade Runner 2: The Edge of Human, Batty is one of a series of replicants based on a mercenary of the same name. The template for these replicants suffered from "neural malformation", which made them unable to experience fear. This, it is suggested, might be one of the reasons replicants of that particular series were so difficult to kill.

Harry Bryant is the captain of the Rep-Detect department of the Los Angeles Police Department. His job in the film is to deal with a group of escaped Nexus-6 replicants (whom he refers to as "skinjobs") that have landed on Earth. His top Blade Runner, Holden, was in hospital on a medical ventilator after an encounter with the Leon replicant, earlier in the film. Bryant uses thinly-veiled threats against Rick Deckard — a retired Blade Runner — to enlist his aid.

In the original theatrical version, Deckard, during his narration, compares Bryant to the racist cops of the past. "Skinjob, that was Bryant's term for Replicants. In history books, he's the kind of cop that used to call black men niggers."

As a fellow cop, he is quickly identified as being very different from Deckard through the ways he dresses and behaves. In the commentaries the cast and crew note that he wears fancy clothing and seems to be part of the precinct's vice squad. He likes to make little Origami-figures. The last words heard in the film are spoken by him: "It's too bad she won't live. But then again, who does?"

Gaff walks with a cane and a noticeable limp.

The sequel by K. W. Jeter mentions that Gaff is killed in the line of duty. At the beginning of the novel, Bryant has just returned from the funeral and expresses his distaste for the Cityspeak written on Gaff's headstone.

Dave Holden is the Blade Runner testing new employees at the Tyrell Corporation on the premise that the escaped Replicants might try to infiltrate the company.

During a Voight-Kampff test, Leon shoots Holden and leaves him for dead. Later, Bryant mentions that Holden is alive, but his breathing is assisted by machines.

There were two hospital scenes with Holden and Deckard that were filmed, but not used in the movie. One scene is shown in the documentary On the Edge of Blade Runner. Both scenes appear in the deleted scenes section on the Blade Runner Special Edition DVD.[citation needed]

Leon Kowalski is a replicant who came to Earth with five others looking to extend their lives. He has an A physical level, which means he has superhuman strength and endurance (according to the Final Cut he was used as a 180 kg/400 lb nuclear-head loader in the outer space colonies as well as a front-line soldier). Leon is classified mental level C. He doesn't have the speed of thought that Roy does when it comes to solving problems. He was activated on April 10, 2017, making him 2 years and 7 months old by the time of the film.

Leon shoots Blade Runner Holden as he administers the Voight-Kampff test on him while he works at the Tyrell Corporation, which he has infiltrated. Leon attacks Deckard after he witnesses Deckard kill Zhora, but is himself killed by Rachael who shoots him with Deckard's gun, which Leon had knocked out of Deckard's hand as he drew it.

Leon cherishes photographs of his friends. Unlike Rachael's false photos of her childhood, these include current photos of people who mean something to him.

Pris Stratton is a "basic pleasure model" (incepted on St. Valentine's Day). She was created on February 14th, 2016, making her 3 years and 9 months old by the time of the film. She is the second oldest replicant after Roy. She meets and becomes friends with J. F. Sebastian. Pris is also the girlfriend of fellow replicant Roy Batty. At an A Physical Level, she is shown to have superhuman endurance (as in the scene where she grabs a boiling egg with her bare hand without harm). Her B Mental Level puts her at a lower intellectual level than Roy. She sets a trap for Deckard in the Bradbury Building, where she disguises herself as a mannequin and uses her gymnastic skills to ambush Deckard; however, she is retired by Deckard.

Her surname Stratton appears in the novel Do Androids Dream of Electric Sheep?, but is never explicitly used in the movie.

Rachael is the latest experiment of Eldon Tyrell. He believes that since the replicants have such a limited lifespan, they have little time to develop control of their emotions, causing difficulty in managing these emotions. He believes implanting the replicants with memories would create a cushion that would allow for emotional development, and make them more controllable.

Rachael has the implanted memories of Tyrell's niece, and Rachael is then led to believe that she is human. It is not revealed in the film how long she has been living, but Tyrell admits that he thinks she is beginning to suspect the truth of her nature.

When Rachael learns the truth, she is ignored by Tyrell. In desperation, she turns to Deckard, who has been told by Captain Bryant to retire her. He eventually falls in love with her.

Both of them are allowed to live: Roy saves Deckard from falling off a building, and Gaff does not kill Rachael. Gaff leaves his calling card, an origami model (this time, foil shaped like a unicorn) at Deckard's apartment to show he's been there. At the end of the film, Rachael and Deckard flee from his apartment to presumably go into hiding, or at least leave the conditions of their former lives.

In Blade Runner 2: The Edge of Human, she is kept within a Tyrell transport that slows down her aging process located in an isolated shack outside of Los Angeles. Near the end of the novel, Sarah Tyrell, who is Eldon's niece and Rachael's template, brings her to Tyrell headquarters in order to meet with Deckard and allowed to flee. However, it is ultimately learned that Rachael is killed by Tyrell agents while Sarah and Deckard escape, allowing Sarah to reclaim her place as Tyrell's niece.

In a deleted scene, Deckard states "[Rachael] was a Nexus-6 with a phony snapshot and phony memories which made her think she was one of us."

J. F. Sebastian is a genetic designer working for Tyrell. He is not allowed to emigrate off-world because he has Methuselah Syndrome. Because of this, he ages faster and has a shorter lifespan, something he has in common with the replicants. He is only 25 years old, but his physical appearance is of a middle-aged man. With the Bradbury Building all to himself, he makes the most of his considerable talents creating automata companions. He is loosely based on the character J. R. Isidore from the novel.

He is approached by Pris, whom Sebastian takes in because he thinks she is homeless, and Roy comes to stay with him soon after. Roy and Pris point out that because of his condition, Sebastian has much in common with them, and argue that if they don't get Tyrell's help to extend their lives, Pris shall die soon. Sebastian is playing correspondence chess with Tyrell, and Roy suggests a bold move which gives rise to an opportunity to visit Tyrell and smuggle Roy in. When Tyrell claims that he cannot extend Roy's life, Roy kills him.

Sebastian is seen running away from Roy, who later descends the elevator alone. A police radio message heard by Deckard after Tyrell is killed states that Sebastian's body was also discovered by the police with Tyrell's at the Tyrell Corporation.

The makeup for Sebastian was a "stretch and stipple" technique with no prosthetics.[2]

Dr. Eldon Tyrell is the genius who has built up the large Tyrell Corporation. His creations are Replicants, some of whom have been given away as an incentive for people to emigrate to the Off-World colonies. Others are used in combat to protect those settlers. Roy Batty, along with J. F. Sebastian, finds Tyrell, and asks him to extend his life beyond the four-year limit built into Nexus Six replicants. However, Tyrell claims this request is impossible to satisfy due to the inherent instabilities of replicant genetics. Upon hearing this, Batty kisses Tyrell before gouging out his eyes and dislocating his skull with his bare hands.

Zhora Salome is a replicant with an A Physical Level (super-human endurance) and a B Mental Level (intelligence equal to that of Pris), and has been used in murder squads. She was activated on June 12, 2016, making her 3 years and 5 months old. She gets a job as an exotic dancer at Taffey's Bar, creating an act using her own pet snake. Deckard tracks her down at Taffey's after finding her snake's scale, and she soon realizes that he is dangerous. She attacks him, but Deckard narrowly escapes death when people walk in just before she delivers a killing blow. Zhora tries to escape by running into a busy street, but Deckard chases her and finally shoots her in the back, "retiring" her.

According to dialogue spoken by Bryant in the Final Cut of the film, two other unnamed replicants (only one in earlier versions) were killed while attempting to enter the Tyrell Corporation. The term used by him when describing their deaths ("Two of them got fried running through an electrical field") suggests they were stopped by an electrical barrier or security device of some sort. (In the theatrical cut of the film, the spoken line is "One of them got fried running through an electrical field" leaving one replicant unaccounted for.)

Earlier drafts of the script name these replicants as Hodge and Mary. In Hampton Fancher's early drafts of the script, Mary lives and Hodge is the only replicant fried in the electrical field. Mary was intended to reflect the novel's character of Irmgard Baty, and was meant to be a "mother figure" model of replicant, performing housework and childcare duties, and she was supposed to be reminiscent of the stereotypical housewife of the 1950s. Her incept date is given as November 1, 2017.[4]Mary was to be played by Stacey Nelkin, who had originally tried out for the role of Pris, but Mary's scenes were cut before filming.[5][6]